Geng Report — Vapour–liquid–solid–solid growth of two-dimensional non-layered β-Bi₂O₃ crystals with high hole mobility (Nature Materials, DOI: 10.1038/s41563-025-02141-w)

Academic fraud report · Geng Detector

Summary

This Geng-style integrity review flags the 2025 Nature Materials paper by Xiong, Zeng and colleagues as "questionable" (🟡), rather than confirming outright fraud. Three textual/quantitative concerns are raised. First, the reported elemental weight percentages of by-product droplets (40% O, 35% Bi, 15% Cl, 5% Na) sum to only 95%, with no account given for the missing 5%, suggesting either an arithmetic slip or fabricated composition values. Second, the abstract advertises a record hole mobility of 136.6 cm² V⁻¹ s⁻¹, while the body text reports an average of 130.4 ± 6.2 cm² V⁻¹ s⁻¹, raising suspicion of selective reporting of the best device. Third, the Methods section contains a unit/grammar error: a "deposition rate" of 30 min (a duration, not a rate). Timeline, reagent and instrument plausibility checks were clean. Pixel-level image-duplication analysis was not performed. Overall verdict: suspicious on data-rigor grounds, but inconclusive pending access to high-resolution figures and raw EDS/XPS data.

Verdict

🟡 Questionable. The report does not establish definitive misconduct but identifies multiple indicators of poor data hygiene and selective reporting that warrant further investigation by the editorial team or institutional reviewers.

Key findings

Elemental composition arithmetic error: droplet analysis lists 40% O, 35% Bi, 15% Cl, 5% Na → sum = 95%, not 100%. Missing 5% is unaccounted for.
Selective reporting of mobility: abstract highlights 136.6 cm² V⁻¹ s⁻¹, while body reports 130.4 ± 6.2 cm² V⁻¹ s⁻¹ (n presumably small).
Methods text error: "deposition rate of 30 min" — minutes is a duration, not a rate, suggesting template-copying rather than careful description.
Timeline & equipment: consistent (Received 2 July 2022; Accepted 15 January 2025; instruments such as FEI Titan3 G2 60-300, HORIBA HR Evo Nano are standard and predate publication).
Pixel-level image checks: not performed; only low-resolution OCR text available.

Evidence highlights

Droplet composition quote (Page 689 / Supplementary Fig. 12): *"40% O, 35% Bi, 15% Cl and 5% Na elements"* → arithmetic total = 95%.
For comparison, crystal-edge composition reported as *"60% O, 39.5% Bi, 0.25% Cl and 0.25% Na"* sums to exactly 100%.
Abstract: "room-temperature hole mobility … of 136.6 cm² V⁻¹ s⁻¹".
Main text: "average hole mobility … to a maximum of 130.4 ± 6.2 cm² V⁻¹ s⁻¹ at 2.4 nm". 136.6 equals the upper bound (130.4 + 6.2) of the stated mean ± SD.
Methods: "The heating and deposition rates were 20 °C min⁻¹ and 30 min, respectively." → unit/term mismatch.
DOI of paper under review: 10.1038/s41563-025-02141-w (Nature Materials, Vol. 24, May 2025).

Notes

Severity ratings assigned by the original report: arithmetic error 🟠; selective mobility reporting 🟡; unit slip 🟡; timeline/equipment ✅ clear; image analysis not feasible (severity unknown).
The arithmetic inconsistency does not automatically imply fabrication, but in a Nature-family submission it is unusual and should be corrected with raw EDS/XPS tables.
The mobility discrepancy is within statistical bounds but exemplifies "cherry-picking"; readers should be given the full device-to-device distribution in the SI.
Pixel-level duplication, splicing, or background-noise consistency checks on Figures (e.g., Fig. 2g HAADF-STEM) require the original TIFF files and were not conducted.
All findings are derived from publicly available PDF text and should be regarded as preliminary pending editorial or institutional review.